Note 10 - Leases (Details Textual) - USD ($) |
3 Months Ended | |||
|---|---|---|---|---|
Mar. 31, 2026 |
Mar. 31, 2025 |
Mar. 02, 2026 |
Dec. 31, 2025 |
|
| Lessee, Operating Lease, Remaining Lease Term (Year) | 16 years 3 months 18 days | |||
| Operating Lease, Right-of-Use Asset | $ 11,100,000 | $ 7,900,000 | ||
| Operating Lease, Liability | 11,379,000 | $ 8,200,000 | ||
| Operating Lease, Expense | $ 427,000 | $ 293,000 | ||
| Operating Lease, Weighted Average Remaining Lease Term (Year) | 8 years 10 months 13 days | |||
| Operating Lease, Weighted Average Discount Rate, Percent | 3.75% | |||
| Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] | Other Assets | Other Assets | ||
| Operating Lease, Liability, Statement of Financial Position [Extensible Enumeration] | Other Liabilities | Other Liabilities | ||
| Middlefield Banc Corp [Member] | ||||
| Operating Lease, Right-of-Use Asset | $ 3,500,000 | |||
| Operating Lease, Liability | $ 3,500,000 | |||
| Maximum [Member] | ||||
| Lessee, Operating Lease, Renewal Term (Year) | 15 years | |||